QT49-8.000MAAJ-B

Overview

The QT49-8.000MAAJ-B is a through-hole quartz crystal manufactured by QST, designed for fundamental mode operation at a nominal frequency of 8 MHz. It features a frequency stability and tolerance of ±30ppm at 25°C and over the temperature range of -20°C to 70°C. The component utilizes an HC-49/US metal package with a load capacitance of 18pF and an equivalent series resistance (ESR) of 80 Ohms. This standard two-pin axial leaded device is suitable for general-purpose clocking applications requiring reliable frequency generation.

Feature Summary

• Fundamental mode quartz crystal oscillator providing stable frequency reference
• HC-49/US metal housing offering robust mechanical protection and shielding
• Through-hole mounting configuration compatible with standard PCB assembly processes

Applications

• Microcontroller clock source circuits
• General-purpose timing references in consumer electronics
• Industrial control system oscillators

Procurement Notes

Verify that the specific ordering suffix matches the required package style and electrical parameters. Confirm that the manufacturer designation aligns with QST specifications rather than other producers using similar part numbering conventions. Ensure the intended operating temperature range meets the design requirements before finalizing procurement orders.

Selection Notes

Select this component when a through-hole HC-49/US crystal is required for 8 MHz applications. Consider the 80 Ohm ESR value to ensure compatibility with the driving circuit's oscillation requirements. Verify that the ±30ppm stability specification satisfies the system's timing accuracy constraints compared to higher precision alternatives.

Part Context

This part belongs to the QT49 series of quartz crystals, which are widely used in electronic circuits requiring precise timekeeping or clock signals. The HC-49/US form factor is a legacy standard still prevalent in many industrial and consumer designs due to its availability and ease of manual or automated insertion.

Replacement Considerations

Direct substitutes include the QT49-8.000MAHK-B from QST, which shares the same frequency but may differ in load capacitance. Other manufacturers producing HC-49/US 8MHz crystals with ±30ppm stability can serve as functional equivalents if pinout and electrical characteristics match.